By the Numbers: Blue-Collars in Eclipse; May 2004; Scientific American Magazine; by Rodger Doyle; 1 Page(s)

In 1840 manufacturing and other manual labor industries employed about 17 percent of the U.S. job force. These employees consisted of a heterogeneous group encompassing artisans, ditchdiggers, sailors and others who worked with their hands. The American blue-collar class began to take shape in the early 20th century, when management engineers wrested control of the manufacturing process from skilled laborers such as machinists to take advantage of the proliferating number of new tools. Through time-and-motion studies, they also prescribed the precise way people should do their jobs.

This "scientific management" in part created assembly-line production, which greatly increased productivity by eliminating the older rhythms of work. But the technique helped to generate millions of boring, closely supervised jobs. Some of the tasks required special clothing, including, in some cases, blue protective gear, which gave the class its name.